Coal metering and cleanout block for stokers



Oct. 2, 1951 E. G. BAER COAL METERING AND CLEANOUT BLOCK FOR STOKEIRS 2Sheets-Sheet 1 Filed March 18, 1949 &

E. G. BAER COAL METERING AND CLEANOUT BLOCK FOR STOKERS Oct. 2, 1951 2Sheets-Sheet 2 Filed March 18, 1949 INVENTOR. Eda/ant G.Ba e1' PatentedOct. 2, 1951 l'T ED STATES PKTE'N T F F ICE COAL METERING AND CLEANOUTBLOCK FOR 'STOKERS 7 Edward G. Baer, 0rrville, 0hi'o as'signor to TheWill-Burt., (1ompany, Orrville, Ohio, a-corporation of- Ohio ApplicationMarch 18, IMQQ'S'e'riaI No. 82158 .2 Claims. 1

The invention relates to stokers in which afeed screwcarriesxcoal from*aehopper through :a coal reed tube to the furnace, and moreparticularly to arcoal metering and cleanout block located adjacenttotheentrance end of the coal :feed tube for varying theamount of coal fedthrough the tube as conditions require.

Inapparatus of the character referredtoiboth thescrew and thetubethrough which coal is .fed by the screw become worn by the continualmovementzof the coal in contact therewithso that in time either thescrew or the :tube, or both, become worn tosuch an extent that duringthe operation of the coal feed screw the tubeis not suflioiently filledwith coal, whereby smoke is permitted to pass back :irom the furnaceback through the coal tube to the hopper.

It, also :happens that where coarse coal is being used, this smoke backcondition prevails. In either-event this is a very annoying andJunpleasant condition, as the smoke passing back through the coal tubeand out of the hopperfills the basement, utility room or other place "inwhich the-hopper is located.

Inrstockers of this character it is customary to provide shear pinswhich will be readily sheared when coal becomes packed in the tube dueto overloading of the screw.

This shear pin is provided to immediately stop the rotation of the coalfeed ,screw when it is overloaded, in order to prevent damage to themotor and drive mechanism which operate the screw. Ihus while the shearpin is necessary in orderto prevent damageto the apparatus, fre

quent shearing of the shear pin is undesirable since-this results in theimmediate stoppage of the-operation of the stocker and requires that thecoal which has become packed in the tube must be removed and the shearpin replaced before the stocker again is ready for operation.

It is an object of the present invention to provide an adjustable coalmetering and cleanout block by means of which the amount of coal fedthrough the coal tube can be varied as conditions require.

Another object is to provide such a metering block having asubstantially semi-cylindrical cutout portion surrounding the feed screwand spaced therefrom providing a clearance between the screw and theblock, with means for increasing this clearance to allow more coal toenter the tube to prevent smoke back conditions resulting either fromthe use of coarse coal or the use of a worn coal tube and/or screw.

A further object is to provide a coal metering block-of the characterreferred to with means for decreasing the clearance between thescrew andthe block so as to "allow less coal to enter the coal tube in order toprevent the shear pin from being sheared by packingof co'alflin thetube.

A still further object-isto provide a coal me tering block of thischaracter having a flangedhead providing acovering for a cleanoutopening adjacent to the entrance to the coal tube.

Another object is to provide for adjusting the coal metering block bymeans of removable gaskets locatedlbetween the flanged head of theb-lock and the housing, whereby the addition or gaskets will increasethe clearance between the block and the screw, and the removal ofgaskets will-decrease this clearance.

nzifurther objectis to provide threaded studs andinuts -for holding theblock in adjusted posi-- tion.

'l -he aboveand-other object's, apparenttfiromthe drawings and followingdescription, may be :attained, th eabove described difiiculties overcomeand the advantages and results obtained by the apparatus, construction,arrangement and oombi-n'a tions which comprise the present invention,apreferred embodiment of which, illustrative of the best mode in whichapplicant has contemplated applying the principle, being set forthdetail in the following description and illustrated in the accompanyingdrawings, in which;

:Figure l is a fragmentary, longitudinal sectional view through theentrance end portion of a coal tube and the adjacent portion of thehopper, with a coal feed screw therein, showing the improved coalmetering and cleanout block to which the invention pertains; and

Eig. -2 a transverse sectional view, taken as on theline 2-4, Fig. 1.

A portion of the housing of a conventional hopper for stokers isindicated generally at Ill], having the rounded bottom wall II andupwardly and outwardly diverging side walls l2. This hopper terminatesat its outlet end in a tubular portion I3, into which the entrance endof the coal tube I4 is inserted, the inner end of said tube abutting theannular shoulder IS in the tubular portion I3 of the hopper.

The discharge end of the hopper has the downwardly and forwardlyinclined top portion IS in which is located a cleanout opening I!surrounded by the annular rib or flange [8.

A conventional coal feed screw l9, having the usual continuous spiralflange 20 thereon, is located through the hopper and the coal tube forconveying coal from the hopper through the tube to the furnace, in thedirection or the arrow shown in Fig. l, as in usual and customarymanner.

The coal metering block to which the invention pertains is indicated at2|, and is provided at its upper end with the flanged head 22 arrangedto extend over the rib orfiange l8 andcover the cleanout opening I1. 7

As shown in Fig. l, the block 2| may be inclined rearwardly within thehopper and the lower portion thereof may be taperedias indicated at 23.The lower portion of the block has the substantially cylindrical cutoutportion 24, adapted to encircle substantially the upper half ofthespiral flange 20 of the screw at this point in the hopper adjacent tothe inlet end of the coal tube.

With the block 2| in the position shown in the drawings, which isconsidered the normal position, the clearance between the screw and theblock is uniform as best shown in Fig. 2. It will be evident that as theblock 2| is raised this clearance is increased and as the block islowered toward the screw, the clearance isdecreased.

For the purpose of adjusting the block 2| toward or away from the screw,any desired number of gaskets, preferably of fiber, as indicated at 25,are placed between the flanged head 22 of the block and the rib [8 ofthe housing.

By increasing the number of gaskets used at xthis point, it will be seenthat the block is raised :so as to increase the clearance between theblock ;and the screw and by removing some of the gaskets, the block maybe lowered so as to decrease the clearance between the block and the:screw.

For the purpose of holding the metering block in adjustedpositionthreaded studs 26 may be mounted in the housing and adapted topass through suitable openings 27 in the flanged head 22 of the block,wing nuts or the like, as indicated at 28, being screwed down againstthe flanged head of the block as shown in the drawings.

From the above it will be obvious that a simple, inexpensive and easilyadjusted metering device is provided for varying the amount of coal fedthrough the tube as conditions may require, whereby smoke backconditions may be corrected by allowin more coal to enter the tube, andoverloading, resulting in the shearing of shear pins from the packing ofcoal, can be corrected by reducing the amount of coal entering the tube.

According to the provisions of the patent stat-1 ntes, I have explainedthe principle of my invention and described one embodiment thereof, butI desire to have it understood that within the scope of the appendedclaims, the invention may be practiced otherwise than as specificallyillustrated and described. 7

I claim: 7

1. In a stoker comprising a hopper, a coal tube communicating with oneend of the hopper, said one end of the hopper having a top walldownwardly inclined toward the coal tube and having a cleanout openingproviding access to the m terior of the hopper from the exteriorthereof, and a coal feed screw located through the hopper and the coaltube, a coal metering block located through said cleanout opening andhaving a semi-cylindrical cutout portion in its underside surroundingsubstantially the upper half of the screw and spaced therefrom, aflanged head upon the upper end of the coal metering block forming blocktoward and from the screw for controlling the amount of coal fed to thecoal tube from the hopper. V

2. In a stoker comprising a hopper, a coal tube communicating with oneend of the hopper, said one end of the hopper having a top walldownwardly inclined toward the coal tube and havingv a cleanout openingprovidin access to the interior of the hopper from the exterior thereof,

and a coal feed screw located through the hopper and the coal tube, acoal metering block located through said cleanout opening and having asemi cylindrical cut-out portion in its underside sur-' roundingsubstantially the upper half of the screw and spaced therefrom, aflanged head upon the upper end of the coal metering block forming .acover for the cleanout opening, and means for adjustably mounting theflanged head upon said inclined top wall of the hopper for closing thecleanout opening and adjusting the coal metering block toward and fromthe screw for controlling" the amount of coal fed to the coal tube fromthe hopper, said means comprising removable annu lar gaskets locatedbetween said flanged head and said inclined top wall and screw meanslocated through the flanged head and inclined top wall.

EDWARD G. BAER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 879,366 Conway Feb. 18, 19081,348,414 Heberling Aug. 3, 1920 1,794,326 Sierer Feb. 24, 193l2,314,706 Johnston Mar. 23, 1943 2,343,707 Roland Mar. 7, 1944:2,452,453 Graham Oct. 26, 1948

